Insectproof portal construction



Dec. 11 3923.

M. R. HUTCHlSON INSECT PROOF PORTAL CONSTRUCTION Filed Sent. 10

WITNERSE$ Fate-rated Dec. ill, N23.

MWAW

'MILLER REESE HUTCHISON, Oil? ORANGE, NEW JERSEY INSEOTIFROOF PORTAL CONSTRUCTION.

Application filed September 10, 1923. Serial No. 682,008.

To all whom it may concern:

Be it known that I, MILLER REESE HU'rcHIsoN, a citizen of the United States, and a resident of Orange, in the county of Essex and State of New Jersey, have invented a new and Improved Insect roof Portal Construction, of which the to lowing is'a full, clear, and exact description. This invention relates to the art of maintaining an unscreened opening in a building, or rather the atmospheric contents thereof, in a condition whereby winged insects are absolutely precluded from passing from the outs de to the inside of the building by way of such opening. Obviously, the present invention'has its greatest value in providing an insect-proof portal or doorway for use with buildings, such as dwellings,

' stores, stables and the like, having continuouslyopen portals for admitting the free passage ofhuman beings pr other creatures, but in regard to which it is desirable to prevent any ossible passage of flying insects.

One of t e prime objects of the present invention is to provide certain improvements in the apparatus of my co-pending application Serial No. 658,069, filed August 18,

- More specifically, among the objects contemplated bythe present invention is that of providing apparatus for utilizing a discovery I have made as to the behavior of the columnar air-blast characteristic of the invention of said application (especiallywhen a different form of rotary fan is em ployed from the one there shown) whereby increased insect-baffling 'efiiciency is obtained, or, perhaps more accurately, whereby such eiiiciency is maintained uniform from top to bottom of the column; thereby, among other advantages, to permit persons to traverse the portal with less appreciation of special air velocity conditions, and to avoid the necessity for and the expense 1ncident to the use of fumes, va ors or liquid particles,.generally odorous, or admixture with the moving air continuously creating such column.

Another particular object of the present invention is to provide means for controlling such column whereby the downward velocity of the air streams forming the column may be predetermined more accurately than heretofore, whereby in turn such 'velocity may be held closely to the ideal minimum required for efficient insect-bafilement. Another particular object of the present invention is to provide a means for controlling such column whereby the cross-section of the same is maintained substantially circular from top to bottom thereof and oposite segments of the column are confined 1n laterally concave side walls of the portal, whereby in turn the insect-bathing efficiency of the portal is further increased.

A further particular object of the present invention is to provide means for controlling such column so as to preclude or reduce swirling air currents therein, even when the column is wholly or chiefly created by a rotary fan at the top or bottom of the portal.

With these and other particular objects in view, the invention consists in certain novel features of construction and combinations and arrangements of parts as will be more fully hereinafter described and pointed out 1 tion aforesaid;

Fig. 2 is a horizontal sectiomtaken on line 22 of F ig. 1, and illustrating very clearly the incorporation in such a portal of one of the features of the present invention, to wit, side walls for the portal of arcuate cross-section Fig. 3 is a view similar to Fig. 1, but illustrating a modified form of blast-generating means, as well as a blast-controlling means which may be employed in association with the blast-creating means of Fig. 1; and

Fig. 4 is a horizontal section, taken on line 4--4 of Fig. 3.

The invention of the application aforesaid was based on a discovery of mine that a downwardly moving air barrier,- and battleularly such a barrier of a columnar character, as distin ished from the moving air sheets hereto ore proposed, is exoeedingl efiicient for the purpose of precluding winged insects, and especially flies, from passing from the outside to the inside of a building by way of a portal in which such air column is maintained; for the reason that the insects are unable to remain in flight when subjected to a down-draft, provided such draft is of sufficient width in the direc' tion of depth of the portal or doorway to prevent an insect from completely traversing the blast in as short a time as the fraction of an instant required for the insect to pass through a thin sheet-like blast. Hence the characteristic columnar blast disclosed in that application; by which is meant a blast having a cross-section any dimension of which is considerable.

According to the present invention, such characteristic columnar blast is still employed; but is created and controlled accord ing to further discoveries of mine. as will immediately below be explained fully in conneetionwith a detailed description of the various structural features of the illustrative embodiments of the drawing.

From such drawing, it will be seen that each of the vestibular portals illustrated, in Figs. 1 and 2 and in Figs. 3 and 4, is in part established by a pair of side walls 5 and in part established by a floor grating 6 forming part of a floor 7. Any building or building sub-division between such a floor 7 and a roof or ceiling as indicated at '8 may be served 'by a portal constructed pursuant to the invention.

In the case of a portalconstructed pursuant to the invention of the present application or of the co-pending application aforesaid, the columnar air blast is delivered from a point near the top of the portal from a rotary fan or blower 9 on a vertical axis; but in the case of the present invention such fan is'preferably one having a plurality of vanes of the kind shown. The side walls 5, of both the portal constructions herein illustrated, are arcuate in cross-section as shown most clearly in Fig. 2. Now

I have discovered that with certain types of fans, especially those having similar vaneelements to those of the fans 9, particularly when installed in a portal as just described and rotated so as to deliver a downward blast, such blast is of substantiallyconstant velocity and true circular.cross-section for an axial distance approximately equal to the effective diameter of the rotor of the fan.

Therefore, an important feature of the present invention, aside from all other fea tures thereof, is a portal construction such that, as shown iii ithe drawing, the effective diameter of the fan 9 is approximately that of the vertical distance between the point of establishment of the up er end of the air column to the lower enr thereof at the grating 6 which forms the floor of the portal.

In the case of both Figs. 1 and 3, the upper end of the column is located immediately below the fan 9.

In the case of Fig. 3, said upper end of the column is thus located, and also located at a point above a swirl-defeating or minimizing means including a fixed grill comprising a plurality of vertically arranged radially extending webs 10, rather thin and comparatively of considerable width transverse to their length. These webs converge toward meeting at the axis of the fan and at their inner ends are suitably secured to a tubular hub 11 and at their outer ends to a band forming part of an annular structure 12 within which fan 9 is located.

In both Figs. 1 and 3, asuitable spider 13 carries at its center a journalling mount 14:, for the shaft of fan 9, such spider being suitably anchored at the outer ends of its legs to the portal construction. It will be noted that in the case of Fig. 3, the spider is anchored inside the annular structure 12.

In both Figs. 1 and 3, a receptacle filled with a suitable liquid, preferably oil, is provided as indicated at 15, for receiving the insects overborne and thrown down by the columnar air blast through floor grating 6.

Referring now particularly to F ig. 1, I have further discovered that the proper columnar air blast may be maintained, and one particularly efficacious for the purpose'intended, if the portal construction of Fig. 1 as hereinabove described be further equipped with an auxiliary suction blower located below the floor grating 6, as indicated at 16. F an or blower 16 is preferably the same general type of rotary fan as the fan 9 at the top of the portal. When a portal or doorway is thus equipped with a force blower at the top, and a suction blower at the bottom, especially when both the fans provided have effective diameters approximately that of the axial length of the column of air above the floor grating 6, and especially when the portal is vestibular and provided with arcuate side walls as at 5,-even with the parts 10, 11 and 12 of Fig.

3 omittcd,the air column may be kept at' cal wind-tunnel, shaped in the present ease like a Venturi tube; but it is essential, asI so far understand the present invention, and as is borne out by actual tests, that the wind tunnel be so constructed about the fan that the fan is located therein considerably below the top of the tunnel, preferably about midway between the top and bottom of the tunnel. Especially with such grill incorporated at the lower end of said annular structure, as above described, and with the grill located immediately below the fan 9, to the end, as 1 have found, that all swirling action in, the air column is almost if not completely throttled, the wind-confining and guiding means provided by the fixed parts of the annular structure 12 above and below the tan 9, when said parts are shaped as shown in Fig. 3, is effective to insure a, vertically downward flowing column of air which is of practically uniform velocity from top to bottom, and which, while easy of passage by a person, is a certain bar to the passage of flying insects of even rather large size. It will be noted that the annular structure 12 is so designed as to have flared top and bottom end portions; with the upper mouth of the tunnel of greater diameter than the lower mouth thereof. So far as experimentation to date has shown, best results are obtained when the tunnel is so designed, as indicated on the drawing, that its upper end portion 12 is flared according to a radius of curvature 1.6 times the diameter of the fan, such flared portion merges gradually with'a cylindrical portion 12 opposite the fan, and said cylindrical portion diverges into a bottom portion 12 outwardly and downwardly fiared'at an angle of to the portion 12".

It may be determined later on and after more extended experimentation that the construction of Fig. 1 in so far as twofans are employed, when equipped with the wind tunnel and anti-swirling means of Fig. 3 oreither of the latter, is the embodiment of the invention to be most preferred.

proximately I claim: 1

1. An insect-proof portal construction comprising a doorway, air-blast producing means above saiddoorway and disposed to direct ahair-blast substantially vertically downward in the form of a column of apcircular. cross-section, said means comprising a rotary fan on a substantially vertical axis, and a vertically disposed tubular structure substantially concentric withvthe fan rotor and providing a substantially vertical wind-tunnel relative to the fan, said structure having its upper end located at a point cdnsidcrably above said rotor.

2. An' insect-proof portal construction comprising a doorway, air-blast producing means above said doorway and disposed to direct an air-blast Substantially vertically downward in the form of a co umn' of approximately circular cross-section, said means comprising a rotary fan on a substantially vertical axis, and a vertically disposed tubular structure substantially concentric with the fan rotor and providing a substantially vertical wind-tunnel relative to the fan, said structure having its upper end located at a point above said rotor, the cross-scctional area of said tunnel decreasing gradually from the upper end of the tubular structure toward the rotor.

v3. An insect-proof portal construction comprising a doorway, air-blast producing means above said doorway and disposed to direct an air-blast substantially vertically downward in the form of a column of approximately circular cross-section, said means comprising a rotary fan on a substantially vertical axis, and a vertically disposed tubular structuresubstantially concentric with the fan rotor and providing a substantial'y vertical wind-tunnel relative to the fan, said fan being located considerably below the top of. the tunnel, and said structure also carrying means below said rotor adapted to reduce swirling tendencies in the air column in the doorway.

l. An insect-proof portal construction comprising a doorway, air-blast producing means above said doorway and disposed to direct an air-blast substantially vertically downward in the form of a column of approximately circuar cross-section, said means comprising a rotary fan on a substantially vertical axis, and a vertically disposed tubular structure substantially concentric with the fan rotor and providing a, substantially vertical wind-tunnel relative to the fan, said structure having its upper end located at a point above said rotor and said tunnel being shaped like a Venturi tube.

5. An insect-proof portal construction comprising a doorway, air-bast producing means above said doorway and disposed to direct an air-blast substantially vertically downward in thei'orm of a column of approximately circular cross-section, said means comprising a rotary fan a substantiall vertical axis, the blades of the fan having a diameter substantially equal to the height of the doorway.

6. An insect-proof portal construction comprising a doorway, air-blast producin means above said doorway and disposed to direct an air-blast substantially vertically downward in the form of a column of approximately circular cross-section, said means comprising a rotary fan on a substantially vertical axis, said doorway being I vestibular and of considerable depth, and

ing of an effective diameter substantially that of the height of said doorway. v 8. An insect-proof portal construction comprising a doorway, air blast producing 5 means above said doorway and disposed to direct an air blast substantially vertically downward in the form of a column of ap" proximately circular cross-section, and a wall on each side of said doorway of armate cross-section, closely enclosing said 10 means whereby to maintain the columnar character of the air.

MILLER REESE HUTCHISON. 

